American apple cells contain an enzyme that turns the tissues brown when an apple is peeled and left for a time. Boiled apple does not go brown. Explain why the boiled apple behaves differently.

I think I got it from recipetips.com

When cooking apples it is not as much of a concern because once they are cooked, the browning will stop. When fresh apples are peeled or cut open, the apple's cells are exposed and react with the oxygen in the air. The reaction that occurs, which is called oxidation, is what turns the apple brown.

Explanation:

Enzymes are proteins. As such they are very specific. When the apple is boiled, the enzyme becomes denatured and as such doesn't turn the apple brown.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: